Biosynthesis of silver nanoparticles using upland cress: purification, characterisation, and antimicrobial activity

Silver nanoparticles have traditionally been synthesised using physical and chemical methods, often requiring expensive equipment and reagents that pose risks to the environment. This work provides a green method for the biosynthesis of silver nanoparticles using leaf extracts from upland cress: Barbarea verna. Natural reducing agents within the leaf extracts of upland cress reduce silver ions from silver nitrates, resulting in the formation of silver nanoparticles. The silver nanoparticles were purified using centrifugation and extraction using Triton X-114. The resulting nanoparticles were characterised using UV–Vis spectroscopy, dynamic light scattering, atomic force microscopy, and scanning electron microscopy. Silver nanoparticles were shown to have a diameter of 30–40 nm with a characteristic UV–Vis absorption peak at 420 nm. Antimicrobial properties of the synthesised silver nanoparticles were also confirmed using S. epidermis and E. coli bacteria.